1. Field of the Invention
The present invention relates generally to liquid delivery systems. More particularly, the invention concerns an apparatus for enteral feeding applications.
2. Discussion of the Invention
When patients are comatose, or for some reason are unable to take nourishment by mouth, enteral feeding becomes necessary. Enteral nutrition, or tube feeding, is typically accomplished by nasogastric administration or by direct delivery of liquids to the stomach via a surgically implanted feeding tube. Parastalic pumps are currently used for nasogastric feeding when gravity flow from an elevated container is insufficient to instill flow or when an exact amount of regulated feeding is necessary. Such devices are cumbersome to use and at times have proven unreliable.
The apparatus of the present invention overcomes the drawbacks of prior art enteral feeding systems by providing a self-contained apparatus which includes an internal energy source that automatically expels prepackaged nutritional liquids from a sealed aseptic container at a desired uniform rate.
Aseptic packaging is, of course, not new. Such packaging is being used more and more in the food industry for packaging fruit juice, milk products and the like. Additionally, some use of aseptic packaging has been made in the medical field for packaging medical solutions.
When the packaged, aseptically filled liquid is a food product, such as fruit juice, the sealed package is typically punctured at a specific site location and the juice is withdrawn through a straw. When the packaged liquid is a medical solution, the package is typically opened, mixed with other components when required and emptied into a traditional, wide-mouth flexible bag solution container for enteral delivery by conventional gravity means and parastalic pump. However, in U.S. Pat. No. 4,826,500 issued to Rantsola, a system for the enteral delivery of a medical solution directly from an aseptic container is there described. In accordance with the methods of the Rantsola patent, the solution is passed from a container through an elongated giving set and metering system into a nasal tube. The container is an aseptic carton having penetrable side walls, with the giving set being provided with a fitting having a fluid passage extending therethrough. The fitting terminates at a carton cooperating portion which includes a first portion for penetrating the carton side walls to form an orifice therein, the orifice establishing fluid communication between the carton interior and the fitting fluid passage, and a second portion for engaging the carton side wall to maintain cooperation between the carton and fitting.
In U.S. Pat. No. 4,688,595, issued to Srebnik, et al, there is described an enteral nutrition delivery system which comprises an integral molded plastic base which includes a first platform to which is secured an infusion pump and a second platform having a recess in which is secured a specially designed bottle containing nutritional fluid to be fed to a patient. A tubing net-work is included for interconnecting the pump, bottle and the patient.
Neither Rantsola nor Srebnik, et al disclose or remotely suggest the novel apparatus of the present invention, which comprises a prefilled, self-contained system, including a unique stored energy source disposed within an aseptic package for delivering the nutritional liquid at a controlled, uniform rate.
Through use of the novel apparatus of the present invention, the disadvantageous current practice of preparing the dry nutrient composition and mixing it with sterile water at the point of use is avoided. The current practice of preparing the dry nutrient composition and mixing with sterile water at point of use has many obvious disadvantages. Historically, the use of this two-step method of treatment preparation has, in part, been driven by the problems resulting from combined solution sterilization, including chemical reactivity of certain nutrient materials under autoclave conditions because of the flexible bag. Prior art practices also typically employ intermittent feeding of the patient. Recent clinical practice now favors continuous feeding rather than intermittent feeding in most cases. In accordance with the present invention, certain drugs, minerals, nutrients and the like are aseptically sealed in a multi-barrier layer, oxygen impermeable, moisture-proof, microorganism-impermeable aseptic dispenser for automatic, on-demand continuous delivery to the patient without the required use of a parastalic pump or external energy sources of any kind.